활성탄에 TiO2를 졸-겔 방법으로 코팅하여 탄소복합전극을 제조하였고 축전식 이온제거(Capacitive deionization : CDI)과정에서 나타난 제염효과에 대하여 고찰하였다. 본 연구에서 TiO2는 전극의 젖음성을 향상시켜 전극과 전해질의 접촉저항을 감소시키고, 전기이중층 흡착량을 증가시킬 수 있으므로 CDI전극재로 활성탄에 코팅하였다. TEM, XRD, XPS로활성탄에 TiO2가 코팅되었는지 확인하였다. 순환전류전압법과 impedance측정 결과 탄소복합전극이 탄소전극보다 전기이중층 용량이 증가하였으며, 전극의 확산저항이 줄어든 것을 확인하였다. 또한 이온제거율을 확인하기 위한 충전-방전 및 이온전도도 평가 결과 전해질 NaCl 1000 μS/cm에서 탄소복합전극이 탄소전극보다 39% 더 많은 이온을 제거하는 것을 확인하였다. 본 연구 결과 CDI용 전극재료 TiO2가 코팅된 탄소복합전극이 탄소전극보다 효과적인 제염효과를 보임을 확인하였다.

Desalination effects of capacitive deionization (CDI) process was studied using TiO2/activated carbon electrode. In order to enhance the wettability of electrode and decrease a electrode resistance, TiO2 was coated on activated carbon. By means of TiO2 coating on activated carbon, electric double layer to adsorption content in CDI process was increased. It was identified from TEM, XRD, and XPS that the activated carbon based on TiO2 composite was fabricated successfully by means of sol-gel method. As a results of cyclic voltammetry and impedance, it was identified that TiO2/activated carbon electrode has more electric double later capacitance and less diffusion resistance than activated carbon. Also charge-discharge and ion conductivity profiles showed that the ion removal ratios of TiO2/activated carbon electrode in NaCl electrolyte of 1000 μS/cm more increased about 39% than that of activated carbon. In conclusion it was possible to identify that the carbon electrode coated TiO2 as electrode material was more effective than raw carbon electrode.